Chad IIRC, if they are using your property, (the image) for profit, (advertising their "Design, build, maintain" business) without your permisson and /or compensating you for using your image, they are breaking copyright laws. You took the image, there for it is your property.
If you send them a cease and desist email, and they dont comply, I believe you have legal grounds for lawsuit. This being internet related, that might mean you get to choose the venue of any court proceedings....and last time I checked, Durham NC was nowhere near Calgary Canada....so traveling up there to defend themselves might not be cost effective.
I'd consider sending them a few hi res images of the cube in its later glory stages, (watermarked with your name all over the place) and explain to them you'd be willing to loan them the images for their business if you were properly compensated.
Ordinarily, I'm the last one to suggest lawsuit for money....but if they're misrepresenting your work for their financial gain, go for it.
Nick